1. Field of the Invention
This invention relates to live front padmounted electrical switchgear, and especially to a fuse mounting bracket assembly which may readily be adapted to pivotally receive one or the other but not both of two distinctly different types of fuses.
2. Description of the Prior Art
Padmounted electrical switchgear for use in electrical distribution systems and particularly underground systems, may be of the air-insulated, live front type in order to provide desirable in-air visibility, in-air switching and in-air installation. Switchgear of this type normally includes fuses to protect the distribution system from fault currents while providing coordination with upstream and downstream protective devices.
Power fuses of the type having fusible conductive elements of silver or nickel-chrome are frequently used to provide necessary circuit protection. These circuit interrupting fuses typically include an elongated tubular insulating body provided with an upper contact surface and a lower contact surface adapted to be engaged with upper and lower switch terminals respectively. The internal fusible element which is designed to melt under a predetermined fault condition is connected to the upper and lower contacts respectively of the fuse. The fuses are pivotally mounted on the lower terminal such that they may be pivoted to an open circuit interrupting position when it is desired to provide for positive interruption of the circuit for maintenance purposes or the like, or instances where it is necessary to replace a blown fuse.
In one widely used, conventional type of power fuse, the lower contact has a pair of aligned, oppositely directed pins adapted to be pivotally received within a mounting bracket carried by a support within the housing of the switchgear. One fuse of this type is available from S & C Electric Company, Chicago, Ill. as Model SML-4Z power fuse. A support bracket for the SML-4Z type fuse is illustrated in Design U.S. Pat. No. 254,614.
In a second type of power fuse, a mounting hook is provided on the lower contact of the fuse for engagement with hook receiving means on a supporting bracket within the switchgear housing. A fuse of this type is available from S & C Electric Company as Model SML-20 power fuse. A support bracket for the SML-20 type fuse is shown in Design U.S. Pat. No. 254,615.
It has been the practice in the past to provide two separate, totally independent brackets for pivotally mounting respective types of power fuses. This required fabrication and stocking of power fuse support brackets for each type of power fuses.